Revert "[objc] Switch to forward declare proto & clean up (#27444)" (#27521)

This reverts commit 4ad495420f.

bazel/objc_grpc_library.bzl

@@ -67,6 +67,7 @@ def objc_grpc_library(name, deps, srcs = [], use_well_known_protos = False, **kw
         srcs = arc_srcs,
         defines = [
             "GPB_USE_PROTOBUF_FRAMEWORK_IMPORTS=0",
+            "GPB_GRPC_FORWARD_DECLARE_MESSAGE_PROTO=0",
         ],
         includes = [
             "_generated_protos",

src/compiler/objective_c_plugin.cc

@@ -132,6 +132,8 @@ class ObjectiveCGrpcGenerator : public grpc::protobuf::compiler::CodeGenerator {
     static const ::std::string kNonNullBegin = "NS_ASSUME_NONNULL_BEGIN\n";
     static const ::std::string kNonNullEnd = "NS_ASSUME_NONNULL_END\n";
     static const ::std::string kProtocolOnly = "GPB_GRPC_PROTOCOL_ONLY";
+    static const ::std::string kForwardDeclare =
+        "GPB_GRPC_FORWARD_DECLARE_MESSAGE_PROTO";
 
     ::std::string file_name =
         google::protobuf::compiler::objectivec::FilePath(file);
@@ -161,6 +163,13 @@ class ObjectiveCGrpcGenerator : public grpc::protobuf::compiler::CodeGenerator {
     {
       // Generate .pbrpc.h
 
+      ::std::string imports;
+      if (framework.empty()) {
+        imports = LocalImport(file_name + ".pbobjc.h");
+      } else {
+        imports = FrameworkImport(file_name + ".pbobjc.h", framework);
+      }
+
       ::std::string system_imports;
       if (grpc_local_import) {
         system_imports =
@@ -200,6 +209,12 @@ class ObjectiveCGrpcGenerator : public grpc::protobuf::compiler::CodeGenerator {
       ::std::string class_declarations =
           grpc_objective_c_generator::GetAllMessageClasses(file);
 
+      ::std::string class_imports;
+      for (int i = 0; i < file->dependency_count(); i++) {
+        class_imports += ImportProtoHeaders(
+            file->dependency(i), "  ", framework, pb_runtime_import_prefix);
+      }
+
       ::std::string ng_protocols;
       for (int i = 0; i < file->service_count(); i++) {
         const grpc::protobuf::ServiceDescriptor* service = file->service(i);
@@ -222,9 +237,12 @@ class ObjectiveCGrpcGenerator : public grpc::protobuf::compiler::CodeGenerator {
 
       Write(context, file_name + ".pbrpc.h",
             file_header + SystemImport("Foundation/Foundation.h") + "\n" +
+                PreprocIfNot(kForwardDeclare, imports) + "\n" +
                 PreprocIfNot(kProtocolOnly, system_imports) + "\n" +
-                class_declarations + "\n" + forward_declarations + "\n" +
-                kNonNullBegin + "\n" + ng_protocols + protocols + "\n" +
+                class_declarations + "\n" +
+                PreprocIfNot(kForwardDeclare, class_imports) + "\n" +
+                forward_declarations + "\n" + kNonNullBegin + "\n" +
+                ng_protocols + protocols + "\n" +
                 PreprocIfNot(kProtocolOnly, interfaces) + "\n" + kNonNullEnd +
                 "\n");
     }

src/objective-c/grpc_objc_internal_library.bzl

@@ -166,6 +166,7 @@ def local_objc_grpc_library(name, deps, testing = True, srcs = [], use_well_know
         srcs = arc_srcs,
         defines = [
             "GPB_USE_PROTOBUF_FRAMEWORK_IMPORTS=0",
+            "GPB_GRPC_FORWARD_DECLARE_MESSAGE_PROTO=0",
         ],
         includes = ["_generated_protos"],
         deps = library_deps,

src/objective-c/tests/RemoteTestClient/RemoteTest.podspec

@@ -49,7 +49,7 @@ Pod::Spec.new do |s|
 
   s.pod_target_xcconfig = {
     # This is needed by all pods that depend on Protobuf:
-    'GCC_PREPROCESSOR_DEFINITIONS' => '$(inherited) GPB_USE_PROTOBUF_FRAMEWORK_IMPORTS=1',
+    'GCC_PREPROCESSOR_DEFINITIONS' => '$(inherited) GPB_USE_PROTOBUF_FRAMEWORK_IMPORTS=1 GPB_GRPC_FORWARD_DECLARE_MESSAGE_PROTO=1',
     # This is needed by all pods that depend on gRPC-RxLibrary:
     'CLANG_ALLOW_NON_MODULAR_INCLUDES_IN_FRAMEWORK_MODULES' => 'YES',
   }

test/cpp/ios/RemoteTestClientCpp/RemoteTestCpp.podspec

@@ -38,7 +38,7 @@ Pod::Spec.new do |s|
 
   s.pod_target_xcconfig = {
     # This is needed by all pods that depend on Protobuf:
-    'GCC_PREPROCESSOR_DEFINITIONS' => '$(inherited) GPB_USE_PROTOBUF_FRAMEWORK_IMPORTS=1',
+    'GCC_PREPROCESSOR_DEFINITIONS' => '$(inherited) GPB_USE_PROTOBUF_FRAMEWORK_IMPORTS=1 GPB_GRPC_FORWARD_DECLARE_MESSAGE_PROTO=1',
     # This is needed by all pods that depend on gRPC-RxLibrary:
     'CLANG_ALLOW_NON_MODULAR_INCLUDES_IN_FRAMEWORK_MODULES' => 'YES',
   }